Bangladesh, June 20 -- The killing of three Indian mariners in a United States military strike on a merchant vessel near the Strait of Hormuz has triggered a fresh debate about the future of US-India relations. While New Delhi and Washington have spent more than two decades building what many policymakers described as one of the defining strategic partnerships of the 21st century, the incident has exposed lingering distrust beneath the surface of an otherwise expanding relationship.

The controversy centers on a US Navy attack on an unarmed merchant vessel operating near Oman during a period of heightened tensions surrounding the US-led blockade of Iranian oil exports. According to reports, the vessel was struck by two Hellfire missiles, ...